1. Field of the Invention
The present invention relates to a photographing apparatus and method, and more particularly, to a photographing apparatus and method in which a time difference between a preliminary flashing and a main flashing can be variably set.
2. Description of the Related Art
A photographing apparatus, such as a camera or a camcorder, typically includes image sensors such as an imaging device, a lens assembly, a diaphragm, a shutter, and the like, so that electric charges generated in response to light arriving in a photographic plane of the imaging device can be read as electric signals in order to record an image. When an amount of light is not sufficient to obtain an appropriate image using a photographing apparatus in a dark environment such as at night or indoors, photographing is performed by increasing the amount of light using a flash unit.
However, when a photo-sensor is not provided in the photographing apparatus in order to reduce the size of the photographing apparatus or a manufacturing cost, it is generally difficult to simultaneously adjust focus or exposure while the amount of flashing light is measured during a main shot in which an image of an object is actually recorded on a recording medium if flashing is only performed once.
Accordingly, preliminary flashing can be performed before main flashing in a main shot in order to measure the required amount of light. Subsequently, focusing or exposure can be adjusted, and then the main shot is performed. In association with this technique, Japanese Patent Application Publication No. 2000-196951 discloses a method of detecting the amount of exposure light during the preliminary flashing, and then optimally adjusting a lens focusing position, white balance, or exposure on the basis of the detection result during the main flashing when the main shot is taken.
Meanwhile, if a time difference between the preliminary flashing and the main flashing is too long when the preliminary flashing is performed before the main flashing, the subject of the main shot may misunderstand the preliminary flashing as the main flashing, and he or she may erroneously move or close his or her eyes during the main shot. Therefore, it may not be possible to obtain an appropriate image.
In addition, in order to accurately detect the amount of exposure light during the preliminary flashing before a main shot, a measurement value of the amount of exposure light should not be saturated, and a flashing period or an exposure period should be appropriately controlled during the preliminary flashing measurement. However, the measurement value of the amount of exposure light is often saturated during the preliminary flashing, and thus, in that case, it can be difficult to detect an appropriate amount of exposure light even while the exposure period in the preliminary flashing was being controlled (for example, when the flash unit is used in a bright indoor environment). In this case, it may be impossible to obtain the appropriate amount of light required for main flashing.